Wednesday, September 13, 2017

Fertile soil is being lost at rate of 24bn tonnes a year through intensive farming , says UN-backed study. A third of the planet’s land is severely degraded. Heavy tilling, multiple harvests and abundant use of agrochemicals have increased yields at the expense of long-term sustainability.

“As the ready supply of healthy and productive land dries up and the population grows, competition is intensifying for land within countries and globally,” said Monique Barbut, executive secretary of the UN Convention to Combat Desertification (UNCCD) at the launch of the Global Land Outlook.

“To minimise the losses, the outlook suggests it is in all our interests to step back and rethink how we are managing the pressures and the competition.”

In the past 20 years, agricultural production has increased threefold and the amount of irrigated land has doubled, notes a paper in the outlook by the Joint Research Centre (JRC) of the European commission. Over time, however, this diminishes fertility and can lead to abandonment of land and ultimately desertification. Decreasing productivity can be observed on 20% of the world’s cropland, 16% of forest land, 19% of grassland, and 27% of rangeland. High levels of food consumption in wealthy countries such as the UK are also a major driver of soil degradation overseas.

“Industrial agriculture is good at feeding populations but it is not sustainable. It’s like an extractive industry, said Louise Baker, external relations head of the UN body. “It’s quite a scary number when you consider rates of population growth, but this is not the end of the line. If governments make smart choices the situation can improve,” Baker said, noting the positive progress made by countries like Ethiopia, which has rehabilitated 7m hectares (17m acres).

The impacts vary enormously from region to region. Worst affected is sub-Saharan Africa, but poor land management in Europe also accounts for an estimated 970m tonnes of soil loss from erosion each year with impacts not just on food production but biodiversity, carbon loss and disaster resilience.

In a series of forecasts on land use for 2050, the authors note that sub-Saharan Africa, south Asia, the Middle East and north Africa will face the greatest challenges unless the world sees lower levels of meat consumption, better land regulation and improved farming efficiency.